The behavior of statically-indeterminate structural members and frames with cracks present

Arts et Métiers ParisTech, invitation en tant que professeur invité de Paul C. Paris au LAMEFIPCrack stability is discussed as affected by their presence in statically-indeterminate beams, frames, rings, etc. loaded into the plastic range. The stability of a crack in a section, which has become plastic, is analyzed with the remainder of the structure elastic and with subsequent additional plastic hinges occurring. The reduction of energy absorption characteristics for large deformations is also discussed. The methods of elastic–plastic tearing instability are incorporated to show that in many cases the fully plastic collapse mechanism must occur for complete failure.The authors acknowledge Arts et Metiers Paris Tech and Foundation Arts et Metiers for the financial support of the Prof. P.C. Paris’ stay at LAMEFIP in 2008 and 2009. The encouragement of Prof. Ivan Iordanoff, Director of LAMEFIP, is also acknowledged with thanks

The Complier Pays Principle: The Limits of Fiscal Approaches Toward Sustainable Forest Management

This paper examines the role and impact of taxation on sustainable forest management. It is shown that fiscal instruments neither reinforce nor substitute for traditional regulatory approaches and can actually undermine sustainability. The paper uses the reasoning at the root of the Faustmann solution to draw conclusions on the incentives for sustainable tropical forest exploitation. It proposes a bond mechanism as an alternative market-based instrument to encourage sustainable forest logging while reducing monitoring costs. Copyright 2001, International Monetary Fund

The behavior of statically-indeterminate structural members and frames with cracks present

Arts et Métiers ParisTech, invitation en tant que professeur invité de Paul C. Paris au LAMEFIPCrack stability is discussed as affected by their presence in statically-indeterminate beams, frames, rings, etc. loaded into the plastic range. The stability of a crack in a section, which has become plastic, is analyzed with the remainder of the structure elastic and with subsequent additional plastic hinges occurring. The reduction of energy absorption characteristics for large deformations is also discussed. The methods of elastic–plastic tearing instability are incorporated to show that in many cases the fully plastic collapse mechanism must occur for complete failure.The authors acknowledge Arts et Metiers Paris Tech and Foundation Arts et Metiers for the financial support of the Prof. P.C. Paris’ stay at LAMEFIP in 2008 and 2009. The encouragement of Prof. Ivan Iordanoff, Director of LAMEFIP, is also acknowledged with thanks

Fatigue crack initiation and growth on a steel in the very high cycle regime with sea water corrosion

The authors acknowledge Arts et Métiers ParisTech and Foundation Arts et Métiers for the financial support of P.C. Paris’ stay at LAMEFIP. They acknowledge Vicinay Cadenas S.A. for its financial support, and both the PCP France-Mexique and the CONACYT for their financial support too.This paper is devoted to the effect of corrosion on the gigacycle fatigue strength of a martensitic–bainitic hot rolled steel used for manufacturing offshore mooring chains for petroleum platforms. Smooth specimens were tested under fully reversed tension between 1E6 and 1E10 cycles in three testing conditions and environments: (i) in air, (ii) in air after precorrosion and (iii) in air under real time artificial sea water flow. The fatigue strength at greater than 108 cycles is reduced by a factor more than five compared with non-corroded specimens. Fatigue cracks initiate at corrosion pits due to pre-corrosion, if any, or pits resulting from corrosion in real time during the cyclic loading. It is shown that under sea water flow, the fatigue life in the gigacycle regime is mainly governed by the corrosion process. Furthermore, the calculation of the mode I stress intensity factor at hemispherical surface defects (pits) combined with the Paris–Hertzberg–Mc Clintock crack growth rate model shows that fatigue crack initiation regime represents most of the fatigue life.PCP France Mexique, Conacyt, Arts et Métiers ParisTech (professeur invité Paul C Paris

Methodology for Carbon Footprint in Forestry Findings and Ways of Improvement

International audienceClassic methodologies for carbon footprint are made for conventional companies or territories. None is well adapted for entire sectors or parts of sectors, which usually contain numerous and very different companies, such in the forestry. In this work, we proposed a methodology to count GHG emissions for forestry in a region, from harvest preparation to the entrance of industries. We divided forestry in three steps: harvesting, forwarding and transport, for which we listed each GHG emitting process. Then, we applied this methodology in the Auvergne region (FR) and estimated GHG emissions to bring one cubic meter of wood to the industry to an average of 4.7 kgCe; with each step (harvesting, forwarding and transport) causing around a third of it. We also estimated related emissions for different types of wood (timber, industrial wood and fuelwood) and finally, we proposed 32 recommendations to reduce GHG emissions in forestry

Gestion informatisée des connaissances pour une agriculture durable

International audienceAgriculture must evolve into a more environmentally-friendly way while being economically workable. This type of agriculture is said to be sustainable. It has a systemic logic and therefore requires a lot of knowledge. Our work is based, on the one hand, on inquiries into the knowledge flows in conventional and sustainable agriculture. On the other hand, we investigate a more theoretical approach based on a state of the art of knowledge management applied to the industrial world. These two approaches lead to show the relevance of developing a sustainable agriculture knowledge management tool. Finally, from two methods, we have identified priority knowledge to capitalize in this tool.L'agriculture devra évoluer vers une agriculture plus respectueuse de l'environnement tout en étant économiquement viable. Ce type d'agriculture est dite durable. Elle a une logique systémique et nécessite donc beaucoup de connaissances. Notre travail repose d'une part sur des enquêtes sur la circulation des connaissances en agriculture conventionnelle et durable, et d'autre part sur une approche plus théorique fondée sur un état de l'art de la gestion des connaissances appliquée au monde industriel. Les deux démarches conduisent à montrer la pertinence de développer un outil de gestion des connaissances en agriculture durable. Enfin, à partir de deux méthodes, nous avons identifié les connaissances prioritaires à capitaliser dans cet outil